The present invention is directed to a primary radiation diaphragm for a radiation apparatus. The diaphragm comprises at least one diaphragm plate adjustable in a plane perpendicular relative to the axis of the central ray of the radiation transmitter or emitter.
U.S. Pat. No. 4,691,335, whose disclosure is incorporated herein by reference thereto and which claims priority from German Application 84 36 281(U), as well as German Published Application 14 41 312, disclose primary radiation diaphragms wherein two diaphragm plate pairs are respectively oppositely adjustable relative to one another in two parallel planes so that a rectangular gating of the x-ray beam is possible. The adjustment of the diaphragm plates lying above one another must, therefore, occur in such a way that only the opening that defines the radiation field is left free. The diaphragm plates are adjustably seated by, respectively, two mounts provided on sides lying opposite one another.